In this invention, an acid treated, aqueous dispersion is provided that improves the oil and water-repellency of materials. The acid-treated, aqueous dispersion comprises at least one polymer, at least one water-dispersible polyester, water, and at least one acid-generating compound; wherein the polymer...http://www.google.com/patents/US7101924?utm_source=gb-gplus-sharePatent US7101924 - Water-dispersible polyester stabilized, acid-treated, fluoroalkyl compositions

In this invention, an acid treated, aqueous dispersion is provided that improves the oil and water-repellency of materials. The acid-treated, aqueous dispersion comprises at least one polymer, at least one water-dispersible polyester, water, and at least one acid-generating compound; wherein the polymer comprises repeating units from at least one fluoroalkyl monomer and optionally, at least one ethylenically unsaturated monomer.

Articles coated with the acid-treated, aqueous dispersion are also provided.

Images(10)

Claims(39)

1. An acid-treated, aqueous dispersion comprising a polymer, at least one water-dispersible polyester, water and at least one acid-generating compound; wherein said polymer comprises repeating units from at least one fluoroalkyl monomer and optionally at least one ethylenically unsaturated monomer; wherein said fluoroalkyl monomer is a (meth)acrylate having a Rf group; and wherein the Rf group is a group having at least two hydrogen atoms of an alkyl group substituted by fluorine atoms.

3. An acid-treated, aqueous dispersion according to claim 2 wherein said acid is sulfonic acid.

4. An acid-treated, aqueous dispersion according to claim 3 wherein said acid is para-toluene sulfonic acid.

5. An acid-treated, aqueous dispersion according to claim 1 wherein said acid-generating compound present in said acid-treated, aqueous dispersion ranges from about 0.01% to about 0.2% based on the weight of said acid-treated, aqueous dispersion.

6. An acid-treated, aqueous dispersion according to claim 1 wherein the carbon number of said Rf group is from 2 to about 20.

7. An acid-treated, aqueous dispersion according to claim 6 wherein the carbon number of said Rf group is from 6 to 14.

8. An acid-treated, aqueous dispersion according to claim 1 wherein the number of fluorine atoms in said Rf group is at least 60%, as represented by [(the number of fluorine atoms in the Rf group)/(the number of hydrogen atoms contained in an alkyl group having the same carbon number as the Rf group)]×100(%).

9. An acid-treated, aqueous dispersion according to claim 8 wherein the number of fluorine atoms in said Rf group is at least 80%, as represented by [(the number of fluorine atoms in the Rf group)/(the number of hydrogen atoms contained in an alkyl group having the same carbon number as the Rf group)]×100(%).

10. An acid-treated, aqueous dispersion according to claim 1 wherein said Rf group is a perfluoroalkyl group.

11. An acid-treated, aqueous dispersion according to claim 10 wherein the number of carbon atoms in said perfluoralkyl group is from 2 to about 20.

12. An acid-treated, aqueous dispersion according to claim 1 wherein the fluoroalkyl monomer is represented by the formula: Rf-Q-OCOCR═CH2; wherein Q is a bivalent organic group, and R is a hydrogen atom or methyl group.

13. An acid-treated, aqueous dispersion according to claim 12 wherein Q is selected from the group consisting of —(CH2)p+q—; —(CH2)pCONH(CH2)q—; —(CH2)pOCONH(CH2)q—; —(CH2)pSO2NR′(CH2)q—; —(CH2)pNHCONH(CH2)q—; or —(CH2)pCH(OH)—(CH2)q—; wherein R′ is a hydrogen or an alkyl group, and each of p and q is an integer of at least 0, provided that p+q is an integer of from 1 to 22.

14. An acid-treated, aqueous dispersion according to claim 13 wherein Q is selected from the group consisting of —(CH2)p+q—; —(CH2)pCONH(CH2)q—; and —(CH2)pSO2NR′(CH2)q—; wherein q is an integer of at least 2; and p+q is from 2 to 6.

15. An acid-treated, aqueous dispersion according to claim 14 wherein Q is —(CH2)p+q, and wherein p+q is from 2 to 6.

16. An acid-treated, aqueous dispersion according to claim 12 wherein said fluoroalkyl monomer is selected from the group consisting of:

F(CF2)5CH2OCOCR═CH2,

F(CF2)6CH2CH2OCOCR═CH2,

H(CF2)6CH2CH2OCOCR═CH2,

F(CF2)8CH2CH2OCOCR═CH2,

i-C3F7(CF2)5CH2CH2OCOCR═CH2,

F(CF2)8SO2N(C3H7)CH2CH2OCOCR═CH2,

F(CF2)8(CH2)4OCOCR═CH2,

F(CF2)8SO2N(CH3)CH2CH2OCOCR═CH2,

F(CF2)8SO2N(C2H5)CH2CH2OCOCR═CH2 ,

F(CF2)8CONHCH2CH2OCOCR═CH2,

i-C3F7(CF2)5(CH2)3OCOCR═CH2,

i-C3F7(CF2)5CH2CH(OCOCH3)OCOCR═CH2,

i-C3F7(CF2)5CH2CH2CH(OH)CH2OCOCR═CH2,

F(CF2)9CH2CH2OCOCR═CH2, and

F(CF2)9CONHCH2CH2OCOCR═CH2; wherein R represents a hydrogen or a methyl group, and i-C3F7 represents a perfluoroisopropyl group [(CF3)2CF—].

17. An acid-treated, aqueous dispersion according to claim 16 wherein said fluoroalkyl monomer is selected from the group consisting of perfluoroalkylethyl acrylate and perfluoroalkylmethyl acrylate.

18. An acid-treated, aqueous dispersion according to claim 17 wherein said fluoroalkyl compound is perfluoroalkylethyl acrylate or perfluoroalkylmethyl acrylate; wherein the alkyl group has about 6 to about 14 carbon atoms.

19. An acid-treated, aqueous dispersion according to claim 1 wherein said ethylenically unsaturated monomer is at least one selected from the group consisting of styrenic compounds, ethylenically unsaturated compounds, nitrogen-containing compounds, vinyl chloride, and vinylidene chloride.

20. An acid-treated, aqueous dispersion according to claim 19 wherein said styrenic compound is at least one selected from the group consisting of styrene, α-methyl styrene, vinyl naphthalene, vinyl toluene, and chloromethyl styrene.

23. An acid-treated, aqueous dispersion according to claim 19 wherein said ethylenically unsaturated monomer has up to about 18 carbon atoms.

24. An acid-treated, aqueous dispersion according to claim 23 wherein said ethylenically unsaturated monomer is at least one selected from the group consisting of 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, and lauryl methacrylate.

25. An acid-treated, aqueous dispersion according to claim 1 wherein the amount of fluoroalkyl monomer repeating units in said polymer ranges from about 50 to about 100 weight percent based on the total weight of monomer utilized to produce said polymer.

26. An acid-treated, aqueous dispersion according to claim 25 wherein the amount of fluoroalkyl repeating units in said polymer ranges from about 60 to about 80 weight percent based on the total weight of monomer utilized to produce said polymer.

27. An acid-treated, aqueous dispersion according to claim 1 wherein said water-dispersible polyester is a polyethylene glycol polyester.

28. An acid-treated, aqueous dispersion according to claim 27 wherein the amount of said water-dispersible polyester solids in the acid-treated, aqueous dispersion range from about 1 to about 20 based on the total weight of said acid-treated, aqueous dispersion.

29. An acid-treated, aqueous dispersion according to claim 1 wherein the amount of polymer ranges from about 10% to about 50% by weight based on the weight of the acid-treated, aqueous dispersion.

30. An acid-treated, aqueous dispersion according to claim 1 wherein the weight average molecular weight of said polymer ranges from about 3,000 to about 2,000,000 as determined by gel permeation chromatography.

31. An acid-treated, aqueous dispersion according to claim 1 further comprising at least one compound selected from the group consisting of other water repellents and oil repellents, anti-fungus agents, flame retardants, antistatic agents, crease-proofing agents, antimigrants, defoamers, binders, and other antifouling agents.

32. An acid-treated, aqueous dispersion comprising at least one polymer, water, at least one nonionic water-dispersible polyester, at least one internal crosslinking agent, at least one external crosslinking agent, at least one reactive surfactant, and a chain transfer agent; wherein said polymer comprises the repeating units derived from at least one fluoroalkyl monomer and at least one ethylenically unsaturated monomer; wherein said ethylenically unsaturated monomer has up to 18 carbon atoms.

33. An acid-treated, aqueous dispersion according to claim 32 wherein the amount of said polymer ranges from about 10% to about 50% by weight based on the weight of the acid-treated, aqueous dispersion, wherein the amount of said water-dispersible polyester solids range from about 1% to about 20% based on the weight of the acid-treated, aqueous dispersion, wherein the amount of said internal crosslinking agent ranges from about 0.1% to about 5% by weight based on the total weight of monomer, wherein the amount of said external crosslinking agent ranges from about 0.1% to about 5% by weight based on the total weight of monomer; wherein the amount of said chain transfer agent ranges from about 0.1 to about 1% by weight based on the total weight of monomer.

35. An acid-treated, aqueous dispersion according to claim 34 wherein the amount of said polymer ranges from about 10% to about 50% by weight based on the weight of the acid-treated, aqueous dispersion, wherein the amount of polyethylene glycol polyester solids range from about 1% to about 20% based on the weight of the acid-treated, aqueous dispersion, wherein the amount of n-methyol acrylamide ranges from about 0.1% to about 5% by weight based on the total weight of monomer, wherein the amount of diallylmaleate ranges from about 0.1% to about 5% by weight based on the total weight of monomer; wherein the amount of n-dodecylmercaptan ranges from about 0.1 to about 1% by weight based on the total weight of monomer.

36. A substrate coated with said acid-treated, aqueous dispersion of claim 1.

37. A substrate according to claim 36 wherein said substrate is selected from the group consisting of a yarn, thread, fiber, fabric, paper material, and carpet.

38. A substrate coated with said acid-treated, aqueous dispersion of claim 32.

39. A fabric coated with said acid-treated, aqueous dispersion of claim 1.

Description

FIELD OF THE INVENTION

This invention is related to compositions that provide oil and water-repellency to articles. Particularly, this invention relates to an acid-treated, aqueous dispersion comprising at least one polymer, at least one water-dispersible polyester, water, and at least one acid-generating compound; wherein the polymer comprises at least one fluoroalkyl monomer and optionally at least one ethylenically unsaturated monomer. More particularly, this invention relates to an acid-treated, aqueous dispersion comprising at least one polymer, a polyethylene glycol polyester, water, and sulfonic acid; wherein the polymer comprises a perfluoroalkyl acrylate and an ethylenically unsaturated monomer.

BACKGROUND OF THE INVENTION

Polymers and other compounds containing fluorinated monomers have been used for providing oil and water repellency to textile substrates, such as, fabrics and paper. These fluoroalkyl polymers are typically produced by emulsion polymerization utilizing either an anionic or a cationic surfactant to stabilize the emulsion. These surfactants used to produce the fluoroalkyl polymers can cause foaming and degradation of the oil and water repellency of the fluoroalkyl polymer contained on the textile substrate. There is a need in the textile industry to develop an aqueous dispersion of a fluoroalkyl polymer utilizing a surfactant that does not foam and degrade the oil and water repellency of the fluoroalkyl polymer.

Applicants provide a novel, oil and water repellent composition comprising at least one polymer and at least one nonionic water-dispersible polyester that reduces foaming and degradation of the oil and water repellency.

BRIEF SUMMARY OF THE INVENTION

It is an object of this invention to provide an acid-treated, aqueous dispersion that provides oil and water-repellency to articles.

It is another object of this invention to provide substrates and articles coated with the acid-treated, aqueous composition.

In accordance with one embodiment of the invention, an acid-treated, aqueous dispersion is provided. The acid-treated, aqueous dispersion comprises at least one polymer, at least one water-dispersible polyester, water, and at least one acid-generating compound; wherein the polymer comprises repeating units from at least one fluoroalkyl monomer and optionally, at least one ethylenically unsaturated monomer.

In accordance with yet another embodiment of the invention, an article coated with the acid-treated, aqueous dispersion is provided.

DETAILED DESCRIPTION

In the present invention, an aqueous dispersion is provided. The aqueous dispersion comprises a polymer, at least one water-dispersible polyester, and water; wherein the polymer comprises the repeating units from at least one fluoroalkyl monomer.

The fluoroalkyl monomer is a (meth)acrylate having a Rf group. The (meth)acrylate having a Rf group is a compound wherein the Rf group is present in the alcohol residue moiety of the (meth)acrylate. The Rf group is a group having at least two hydrogen atoms of an alkyl group substituted by fluorine atoms.

The carbon number of the Rf group is from 2 to about 20, preferably from about 4 to about 16, and most preferably from 6 to 14. The Rf group is preferably a straight chain or branched group. In the case of a branched group, the branched moiety is present at the terminal portion of the Rf group and preferably a short chain having from 1 to 4 carbon atoms. The Rf group may contain other halogen atoms in addition to fluorine atoms. As such, chlorine atoms are preferred. Further, an etheric oxygen atom may be inserted between carbon atoms in the Rf group.

The number of fluorine atoms in the Rf group is preferably at least about 60%, more preferably at least 80%, as represented by [(the number of fluorine atoms in the Rf group)/(the number of hydrogen atoms contained in an alkyl group having the same carbon number as the Rf group)]×100(%). Further, the Rf group is preferably a group having all of hydrogen atoms of an alkyl group substituted by fluorine atoms (i.e. a perfluoroalkyl group).

The number of carbon atoms in the perfluoroalkyl group is preferably from 2 to about 20, more preferably from about 4 to about 16, and most preferably from 6 to 14. If the carbon number is less than 2, the water repellency and oil repellency of the aqueous dispersion tend to be low. If the carbon number exceeds 20, the (meth)acrylate having a perfluoroalky group tends to be solid at room temperature making handling difficult.

In one embodiment, the fluoroalkyl monomer is represented by Formula 1:
Rf-Q-OCOCR═CH2 (1)
wherein Rf is defined as discussed previously, Q is a bivalent organic group, and R is a hydrogen atom or a methyl group. Q is preferably (CH2)p+q—; —(CH2)pCONH(CH2)q—; —(CH2)pOCONH(CH2)q—; (CH2)pSO2NR′(CH2)q—; —(CH2)pNHCONH(CH2)q— or —(CH2)pCH(OH)—(CH2)q—, wherein R′ is a hydrogen or an alkyl group, and each of p and q is an integer of at least 0, provided that p+q is an integer of from 1 to 22. It is preferred that Q is —(CH2)p+q—; —(CH2)pCONH(CH2)q—; —(CH2)pSO2NR′(CH2)q—; wherein q is an integer of at least 2; and p+q is from 2 to 6. Particularly preferred is —(CH2)p+q, wherein p+q is from 2 to 6.

Specific examples of the (meth)acrylate having a Rf group include, but are not limited to:

F(CF2)5CH2OCOCR═CH2,

F(CF2)6CH2CH2OCOCR═CH2,

H(CF2)6CH2CH2OCOCR═CH2,

F(CF2)8CH2CH2OCOCR═CH2,

i-C3F7(CF2)5CH2CH2OCOCR═CH2,

F(CF2)8SO2N(C3H7)CH2CH2OCOCR═CH2,

F(CF2)8(CH2)4OCOCR═CH2,

F(CF2)8SO2N(CH3)CH2CH2OCOCR═CH2,

F(CF2)8SO2N(C2H5)CH2CH2OCOCR═CH2,

F(CF2)8CONHCH2CH2OCOCR═CH2,

i-C3F7(CF2)5(CH2)3OCOCR═CH2,

i-C3F7(CF2)5CH2CH(OCOCH3)OCOCR═CH2,

i-C3F7(CF2)5CH2CH2CH(OH)CH2OCOCR═CH2,

F(CF2)9CH2CH2OCOCR═CH2, and

F(CF2)9CONHCH2CH2OCOCR═CH2.
In these examples, R represents a hydrogen or a methyl group, and i-C3F7 represents a perfluoroisopropyl group [(CF3)2CF—].

Two or more types of fluoroalkyl monomers may be used in combination. Preferably, the fluoroalkyl monomer is selected from the group consisting of perfluoroalkylmethyl acrylate and perfluoroalkylethyl acrylate. More preferably, the fluoroalkyl compound is perfluoroalkylethyl acrylate or perfluoroalkylmethyl acrylate; wherein the alkyl group has about 6 to about 14 carbon atoms. Most preferably, the fluoroalkyl compound is perfluoroalkylethyl methacrylate

In another embodiment of this invention, the polymer in the aqueous dispersion comprises the repeating units from at least one fluoroalkyl monomer and from at least one ethylenically unsaturated monomer. The ethylenically unsaturated monomer is at least one acrylic or vinyl monomer known in the art capable of polymerizing with the fluoroalkyl monomer. The ethylenically unsaturated monomer can be added as a single type of monomer or as a mixture. Examples of suitable ethylenically unsaturated monomers, include, but are not limited to, styrenic compounds, ethylenically unsaturated compounds, nitrogen-containing compounds, vinyl chloride, and vinylidene chloride.

Two or more of the ethylenically unsaturated monomers may be used in combination. Preferably, the ethylenically unsaturated monomer has up to about 18 carbon atoms, such as, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, lauryl methacrylate and stearyl methacrylate. Most preferably, the ethylenically unsaturated monomer is lauryl methacrylate.

The amount of fluoroalkyl monomer repeating units in the polymer ranges from about 50 to about 100 weight percent based on the total weight of monomer utilized to produce the polymer. Preferably, the amount of fluoroalkyl repeating units in the polymer ranges from 60 to 80 weight percent based on the total weight of monomer utilized to produce the polymer.

The weight average molecular weight (Mw) of the polymer ranges from about 3000 to about 2,000,000, preferably 10,000 to 500,000 as determined by gel permeation chromatography.

The water-dispersible polyester can be any water-dispersible polyester that is known in the art capable of emulsifying the fluoroalkyl monomer, and optionally, the ethyleneically unsaturated monomer and stabilizing the aqueous dispersion. The water-dispersible polyester can be either a nonionic or anionic water-dispersible polyester. Examples of water-dispersible polyesters sold by Eastman Chemical Company include LUBRIL QC, LUBRIL QCX, LUBRIL QCF, LUBRIL QCJ, VELVETOL 1471, and VELVETOL 251C. Other water-dispersible polyesters include MILEASE T, MILEASE HPA, HILEASE NUVA, and AFILAN 8228 sold by Clariant, and ASTRAPLUSH and TANAPAL ACF sold by Bayer. Preferably, the water-dispersible polyester is nonionic. Polyethylene glycol polyester is the preferred water-dispersible polyester. Polyethylene glycol polyester is available from Eastman Chemical Company as LUBRIL QC. The amount of water-dispersible polyester solids in the aqueous dispersion ranges from about 1% to about 20% based on the total weight of the aqueous dispersion, preferably from about 1% to about 5%, and most preferably 3% to 5%.

The aqueous dispersion may be prepared by any polymerization method known in the art. In one embodiment, a process to produce an aqueous dispersion is provided. The process comprises: 1) contacting at least one fluoroalkyl monomer, at least one water-dispersible polyester, water, and optionally an ethylenically unsaturated monomer to produce a mixture; and 2) polymerizing the mixture to produce the aqueous dispersion.

Preferably, the aqueous dispersion is prepared by using emulsion polymerization techniques. The polymer may, as is known in the art, be prepared using free radical emulsion polymerization techniques that yield structured or unstructured particles. Structured particles include, for example, core/shell particles, raspberry particles, and gradient particles. The process is carried out in an emulsion polymerization zone comprising at least one reactor in the presence of an initiator. Generally, the reactor is fitted with a stirrer and external means for either heating or cooling the charge. The polymerization temperature is not particularly limited to a certain value, but is preferably from about 20° C. to about 155° C., and most preferably from 40° C. to 85° C.

Any initiator known in the art for emulsion polymerization can be utilized. Typical initiators include, but are not limited to, hydrogen peroxide, potassium or ammonium peroxydisulfate, dibenzoyl peroxide, lauryl peroxide, ditertiary butyl peroxide, ammonium persulfate, alkali persulfuate, 2,2′-azobisisobutyronitrile, t-butyl hydroperoxide, benzoyl peroxide, dicetyl peroxydicarbonate, tertiarybutylperoxy neodecanoate, tertiarybutylperoxy benzoate, cumene hydroperoxide, dicumylperoxide, di-benzoyl peroxide, 2,2′azobis(2-aminopropane)dihydrochloride, 2,2′-azobis[2-(2-imidazolin-2-yl)propane]dihydrochloride and the like. Preferably, the initiator is 2,2′azobis(2-aminopropane)dihydrochloride. The amount of initiator utilized in the polymerization process is that which is sufficient to polymerize the fluoroalkyl monomer and optionally, the ethylenically unsaturated monomer. Preferably, the amount of initiator ranges from about 0.2 to about 1% by weight based on the total amount of monomer, most preferably, 0.1 to 0.2% by weight.

One advantage of this inventive process is that water-soluble organic solvents are not necessary to improve the emulsifiability, therefore, the aqueous dispersion has less volatile organic compound content than other fluoroalkyl aqueous dispersions utilizing solvents. However, water-soluble organic solvents can be used to produce the inventive aqueous dispersions. Examples of water-soluble organic solvents include, but are not limited to, acetone, methyl ethyl ketone, ethyl acetate, propylene glycol, dipropylene glycol, tripropylene glycol, ethanol and the like. The water-soluble organic solvent is usually used in the amount of not more than about 30 parts by weight, preferably from 5 to 20 parts by weight, based on 100 parts by weight of the total amount of monomer.

Reducing agents, catalysts, chain transfer agents, crosslinking agents, reactive surfactants, and water-dispersible/water-soluble polymers known in the art may be used to prepare the polymer. The sequence of addition of these compounds can vary, and these compounds can be added to the polymerization process at varying times.

Suitable reducing agents are those that increase the rate of polymerization and include for example, sodium sulfite, sodium bisulfite, sodium metabisulfite, sodium hydrosulfite, sodium formaldehyde sulfoxylate, sodium thiosulfate, ascorbic acid, isoascorbic acid, and mixtures thereof. The amount of reducing agent ranges from about 0.1% to about 2% based on the total weight of the monomers, preferably from 0.1% to 0.3% based on the total weight of the monomers.

Polymerization catalysts are those compounds which increase the rate of polymerization and which, in combination with the previously described reducing agents, may promote decomposition of the initiator under reaction conditions. Suitable catalysts include, but are not limited to, transition metal compounds such as, for example, ferrous sulfate heptahydrate, chelated forms of ferrous sulfate heptahydrate, ferrous chloride, cupric sulfate, cupric chloride, cobalt acetate, cobaltous sulfate, and mixtures thereof. Generally, the amount of catalyst ranges from about 0.0001% to about 0.05% based on the total weight of the monomers, preferably from 0.001% to 0.01°%.

Any chain transfer agent known in the art may be utilized that is capable of controlling the molecular weight of the polymer. Exemplary chain transfer agents include, but are not limited to, butyl mercaptan, mercaptopropionic acid, 2-ethylhexyl 3-mercaptopropionate, n-butyl 3-mercaptopropionate, octyl mercaptan, N-dodecyl mercaptan, isodecyl mercaptan, octadecyl mercaptan, mercaptoacetic acid, allyl mercaptopropionate, allyl mercaptoacetate, crotyl mercaptopropionate, crotyl mercaptoacetate, carbon tetrabromide, bromoform, bromotrichloromethane, sodium hypophosphite and the reactive chain transfer agents taught in U.S. Pat. No. 5,247,040, incorporated herein by reference. In particular, N-dodecyl mercaptan represents a preferred chain transfer agent. Generally, the amount of the chain transfer agent added ranges from about 0.1 to about 1% by weight based on the total amount of monomer, preferably from 0.1 to 0.3% by weight.

Crosslinking agents can be any compounds that are known in the art and can be used to impart improved crosslinking, latex stability and substantivity to the polymer. The crosslinking agents can be external or internal crosslinking agents. External crosslinking agents cause crosslinking during drying or curing of a polymer while internal crosslinking agents cause crosslinking to occur during polymerization.

Suitable external crosslinking agents include, but are not limited to, poly(oxyethylene) (meth)acrylates, N-methylol acrylamide or N-methylol methacrylamide, N-butoxymethyl acrylamide, hydroxylethyl(meth)acrylate, 2-hydroxybutyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, 3-chloro-2-hydroxypropyl(meth)acrylate, and glycidyl(meth)acrylate. An example of poly(oxyethylene) (meth)acrylates include polyethylene glycol methacrylate. The amount of external crosslinking agent can range from about 0.1 to about 5% by weight based on the total amount of monomer, preferably from 2 to 3% by weight based on the total amount of monomer.

In the preparation of the aqueous dispersion, fluoroalkyl monomers, such as described previously, can be reacted with at least one non-self-polymerizable, surface-active vinyl monomer (also known as a non-self-polymerizable ethylenically-unsaturated surfactant or a reactive surfactant). Non-self-polymerizable, surface-active vinyl monomers will hereinafter be referred to as a reactive surfactant. The reactive surfactant, rather than polymerizing to form a separate polymeric surfactant, is substantially (preferably completely) incorporated into the polymer of the invention. Thus, the reactive surfactant becomes part of the polymer. Reactive surfactants possessing, for example, isopropenylphenyl or allyl groups are preferred. Examples include reactive surfactants sold by PPG Industries, Inc., as MAZON® SAM 181, 183, 184, 211 surfactants which are anionic sulfates or sulfonates and MAZON® SAM 185–187 surfactants which are nonionic surfactants. Other reactive surfactants include the macro monomers sold by Daiichi Kogyo Seiyaku under the names NIOGEN RN, AQUARON or HITENOL surfactants. These include polyoxyethylene alkyl phenyl ether compounds of the general formulae (2), (3), and (4):

In Formulae (2), (3), and (4), R is nonyl or octyl, and n and m are preferably integers of from 15 to 50 and 15 to 40, respectively. More preferably, n ranges from 20 to 40, and m from 15 to 25. HITENOL RN, HITENOL HS-20 and HITENOL A-10 products are particularly preferred reactive surfactants. Other such reactive surfactants include the sodium alkyl allyl sulfosuccinate sold by Henkel, under the trade name TREM LF-40 surfactant.

Water-dispersible and water-soluble polymers may also be employed as surfactants/stabilizers in the aqueous dispersion of the invention. Examples of such polymeric stabilizers include water-dispersible polyurethanes as described in U.S. Pat. Nos. 4,927,876 and 5,137,961; and alkali-soluble acrylic resins as described in U.S. Pat. No. 4,839,413; both of which are herein incorporated by reference.

In one embodiment of this invention, the aqueous dispersion is produced by a process comprising: 1) contacting at least one fluoroalkyl monomer, at least one water-dispersible polyester, water and optionally, at least one ethylenically unsaturated monomer to form an pre-emulsion; and 2) polymerizing the pre-emulsion in a emulsion polymerization zone under emulsion polymerization conditions to produce the aqueous dispersion. The emulsion polymerization zone comprises at least one reactor.

The fluoroalkyl monomer, ethylenically unsaturated monomer, polyester, and initiator can be contacted in the emulsion polymerization zone in any order. The pre-emulsion can be charged all at once (one shot method) to the emulsion polymerization zone, or the pre-emulsion can be charged gradually over time to the emulsion polymerization zone (gradual addition method). In the gradual addition method, pre-emulsion and initiator are charged to the emulsion polymerization zone over a period of time ranging from about 1 to about 10 hours, preferably, from about 2 to 8 hours. The initiator can be added similarly either by a one shot method or gradual addition method.

In another embodiment, the aqueous dispersion can be produced by a process comprising: 1) contacting at least one fluoroalkyl monomer, at least one water-dispersible polyester, water, and optionally, at least one ethylenically unsaturated monomer to form a pre-emulsion; 2) shearing the pre-emulsion to produce a miniemulsion; and 3) polymerizing the miniemulsion in an emulsion polymerization zone under emulsion polymerization conditions to produce the aqueous dispersion.

Shearing of the pre-emulsion produces the mini-emulsion. The shearing can be conducted by any means known in the art. Generally, shearing can be achieved using a high shearing device to form droplets ranging in size from about 50 to about 1000 nanometers to form the mini-emulsion. An example of a high shearing device is a homogenizer.

The miniemulsion can be charged all at once (one shot method) to the emulsion polymerization zone, or the miniemulsion can be charged gradually over time to the emulsion polymerization zone (gradual addition method). In the gradual addition method, miniemulsion and initiator are charged to the emulsion polymerization zone over a period of time ranging from about 1 to about 10 hours, preferably, from about 2 to 8 hours. The initiator can be added similarly either by a one shot method or gradual addition method.

The mini-emulsion, as described above, may also be polymerized as described in U.S. Pat. No. 5,686,518 and Wang et al., “Emulsion and Miniemulsion Copolymerization of Acrylic Monomers in the Presence of Alkyd Resin,” Journal of Applied Polymer Science, Vol. 60, pp. 2069–2076 (1996), each of which is incorporated in its entirety by reference.

In another embodiment of this invention, a process to produce an aqueous dispersion is provided. The process comprises:

1) contacting at least one fluoroalkyl monomer, at least one ethylenically unsaturated monomer having up to 18 carbon atoms, water, at least one water-dispersible polyester, at least one internal crosslinking agent, at least one external crosslinking agent, at least one reactive surfactant, and at least one chain transfer agent to produce a pre-emulsion;

2) shearing the pre-emulsion to produce a mini-emulsion;

3) adding the pre-emulsion to an emulsion polymerization reactor;

4) contacting at least one water-dispersible polyester with water to produce a polyester/water mixture and routing the polyester/water mixture to the emulsion polymerization reactor;

5) contacting at least one initiator and water to produce an initiator solution and routing the initiator solution to the emulsion polymerization reactor to produce a reaction mixture; and

6) polymerizing said reaction mixture to produce the aqueous dispersion.

In another embodiment of this invention, a process is provided to produce an aqueous dispersion. The process comprises:

4) contacting a polyethylene glycol polyester dispersion with water to produce a polyester/water mixture and routing the polyester/water mixture to the emulsion polymerization reactor;

5) contacting at least one initiator and water to produce an initiator solution and routing the initiator solution to the emulsion polymerization reactor to produce a reaction mixture; and

6) polymerizing the reaction mixture to produce the aqueous dispersion.

In still another embodiment of this invention, a process to produce an aqueous dispersion is provided. The process comprises:

1) contacting at least one fluoroalkyl monomer, at least one ethylenically unsaturated monomer having up to 18 carbon atoms, water, at least one water-dispersible polyester, at least one internal crosslinking agent, at least one external crosslinking agent, at least one reactive surfactant, and at least one chain transfer agent to produce a pre-emulsion;

2) shearing the pre-emulsion to produce a mini-emulsion;

3) contacting at least one water-dispersible polyester with water to produce a polyester/water mixture and routing the polyester/water mixture to an emulsion polymerization reactor;

4) contacting at least one initiator and water to produce an initiator solution;

5) adding a portion of said initiator feed to the emulsion polymerization reactor; and

6) charging the miniemulsion and initiator solution to the emulsion polymerization reactor over a period of about 1 to about 10 hours under polymerization conditions to produce the aqueous dispersion.

In yet another embodiment of this invention, a process to produce an aqueous dispersion is provided. The process comprises:

3) contacting a polyethylene glycol polyester dispersion with water to produce a polyester/water mixture and routing the polyester/water mixture to an emulsion polymerization reactor;

4) contacting at least one initiator and water to produce an initiator solution;

5) adding a portion of said initiator feed to the emulsion polymerization reactor; and

6) charging the miniemulsion and initiator solution to the emulsion polymerization reactor over a period of about 1 to about 10 hours under polymerization conditions to produce the aqueous dispersion.

The aqueous dispersion of this invention generally has a polymer concentration ranging from about 10% to about 50% based on the weight of the aqueous dispersion, preferably 20% to 30%. The aqueous dispersion obtained by this invention may be used by itself as it is obtained from the emulsion polymerization zone or it can be purified to remove, for example, unreacted monomers. Further, the composition of the aqueous dispersion may be adjusted by adding a surfactant or by diluting with water or an aqueous medium. In addition, various additives can be added to the aqueous dispersion after it is produced. Such additives include, but are not limited to, other water repellents and oil repellents, anti-fungus agents, flame retardants, antistatic agents, crease-proofing agents, antimigrants, deformers, binders, and other antifouling agents.

In another embodiment of this invention, an acid-generating compound is added to the aqueous dispersion to produce an acid-treated aqueous dispersion. The acid-generating compound can be any that is known in the art. Examples of the acid-generating compound include, but are not limited to, sulfuric acid, hydrochloric acid, phosphoric acid, phosphorous acid, acetic acid, hydroxy acetic acid, citric acid, sulfonic acid and their respective salts formed by ammonia, amines, aminoalcohols, and alkali metal and alkaline earth metal hydroxides. Sulfonic acids include alkyl sulfonic acids and aromatic sulfonic acids. Most preferably, para-toulene sulfonic acid is used.

The acid-generating compound can be added prior to, during, or after polymerization. Generally, the amount of the acid-generating compound is that which is sufficient to improve the oil and water repellency of a substrate contacted with the acid-treated aqueous dispersion when compared to an aqueous dispersion not treated with the acid-generating compound. Preferably, the amount of the acid-generating compound added to the aqueous dispersion ranges from about 0.01% by weight to about 0.4% by weight based on the weight of the aqueous dispersion, preferably 0.01 to 0.2% by weight.

The aqueous dispersion or the acid-treated aqueous dispersion of the present invention is applied by a method of coating on the surface of a substrate to be treated according to a known process such as dip coating, followed by drying or a method of spraying a treating liquid by a spray.

The substrate to be treated with the aqueous dispersion or acid-treated aqueous dispersion of the present invention may be any textile or paper material and is not specifically limited. Examples of the textile include, but are not limited to, animal- or vegetable-origin natural fibers such as cotton, hemp, wool, silk, etc.; synthetic fibers such as polyamide, polyester, polyvinyl alcohol, polyacrylonitrile, polyvinyl chloride, polypropylene, etc.; semisynthetic fibers such as rayon, acetate, etc.; and a mixture of these fibers. The textile may be in any form such as a fiber, a yarn, a fabric and the like. When the textile is a carpet, the carpet may be formed from fibers or yarns treated with the aqueous dispersion or acid-treated aqueous dispersion of the present invention. Alternatively, the carpet itself may be treated with the aqueous dispersion or acid-treated aqueous dispersion of the present invention.

This invention can be further illustrated by the following examples of preferred embodiments thereof, although it will be understood that these examples are included merely for purposes of illustration and are not intended to limit the scope of the invention unless otherwise specifically indicated.

5Wako VA-044 is 2,2′-Azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride with CAS# 27776-21-2 and was obtained from Wako Chemicals U.S.A., Inc.

Components 1–6 were charged to a 1400 mL beaker to produce a pre-emulsion. The beaker was heated to 140° F. to 150° F. and stirred uniformly for 5 minutes. The pre-emulsion was routed two times through a Microfluidics homogenizer to produce a miniemulsion having a particle size of less than 300 nm. The miniemulsion was added to a reaction flask.

Components 9 and 10 (polyester and deionized water) were charged to a reaction flask. Nitrogen purge was started, and the contents of the flask were heated to 140 to 150° F. The reaction flash was set up for reflux.

Components 7 and 8 (initiator and water) were mixed to produce an initiator solution, and the initiator solution was added to the reaction flask. The temperature of the reaction flask was held at 140° F. to 150° F. for 6 hours. The reaction flask was cooled to 100° F., and the nitrogen purge turned off. The aqueous dispersion was recovered from the reaction flask and filtered.

5Wako V-50 is 2,2′-azobis(2-aminopropane)dihydrochloride with CAS # 2997-92-4 and was obtained from Wako Chemicals U.S.A., Inc.

Components 1–8 were charged to a 1400 mL beaker to produce a pre-emulsion. The beaker was heated to 150° F. to 160° F. and stirred uniformly for 5 minutes. The pre-emulsion was routed four times through a Microfluidics homogenizer to produce a miniemulsion having a particle size of less than 300 nm.

Components 13 and 14 (deionized water and water dispersible polyester) were charged to the resin flask. Medium agitation was started, and the flask was heated to a temperature in a range of 140° F. to 150° F.

Components 11 and 12 (initiator and deionized water) were mixed to produce an initiator solution and charged to the side feed. Nitrogen purge was started, and the contents of the flask were heated to 140 to 150° F.

Components 9 and 10 (initiator and deionized water) were mixed together and added to the flask.

The miniemulsion and initiator solution were charged separately to the flask over a 4 hour period. After the miniemulsion and initiator solution were added, components 15 and 16 (initiator and deionized water) were mixed together and added to the flask. The temperature was held for one hour to complete the polymerization producing an aqueous dispersion. The flask was then cooled to 100° F. or below. The nitrogen purge was ended, and the flask was stirred for another 10 minutes prior to recovering the aqueous dispersion.

Components 17 and 18 (acid-generating compound and water) were mixed together and added to the aqueous dispersion to produce the acid-treated aqueous dispersion.

Example 3Foaming Evaluation

A 1.0% by weight aqueous dispersion of the various fluorocarbon compositions in Table 3 was made. 50 milliliters of the dispersion were poured into a 200 millilter graduated cylinder. A stopper was placed in the graduated cylinder, and the cylinder was inverted 20 times. The level of foam in milliliters was measured from the original level of aqueous dispersion in the graduated cylinder. The data are tabulated in Table 3.

TABLE 3

Examples #

Fluorocarbon Composition

Foam (ml)

Inventive 3.1

Acid-Treated Aqueous

11

Dispersion

Inventive 3.2

Acid-Treated Aqueous

10

Dispersion

Comparative 3.1

APG-7052

14

Comparative 3.2

APG-52642

14

Comparative 3.3

APG-102

16

Comparative 3.4

APG-142

11

Comparative 3.5

APG 52332

24

Comparative 3.6

Repearl F 843

21

Comparative 3.7

Repearl F 80253

19

Comparative 3.8

Zonyl 54104

14

Comparative 3.9

Zonyl 84124

15

1Inventive acid-treated aqueous dispersions.

2Fluoroalkyl dispersion obtained from Advanced Polymer, Incorporated.

3Fluoroalkyl dispersion obtained from Mitsubishi International.

4Fluoroalkyl dispersion obtained from Dupont.

From the above data, it is clearly shown that the inventive acid-treated aqueous dispersion reduced foaming over the comparative fluorocarbon dispersions.

Example 4Oil and Alcohol Repellency

The components contained in Table 4 were mixed together to produce an oil and water-repellent composition. Different fluorocarbon dispersions as shown in Table 5 were utilized to produce varying oil and water repellent compositions. Each oil and water-repellent composition was then padded on 100% polyester terephthalate stitchbonded fabric at 40 psig to produce a coated fabric. The coated fabric was then dried for 3 minutes at 350° F. to produce a cured, coated fabric. The cured, coated fabric was then tested for repellency according to the American Association of Textile Chemist and Colorists (AATCC) Technical Manual Method 118-2002.

To summarize the method, the cured, coated fabric was laid on a flat surface. A pipette was used to place 3 single drops of specified alkane or alcohol/water solution on the surface of the cured, coated fabric. After 30 seconds, the appearance of the drops was rated to a photo scale. The ratings are associated with the particular alkane or alcohol/water solution in question.

From these data, it is shown that the inventive acid-treated aqueous dispersion had superior performance over the comparative examples and failed only to repel n-heptane. Comparative example 5.1 passed the repellency test for Drakeol #34, however, it had a borderline pass for repellency of isopropanol and n-decane and had complete wetting of the fabric for n-heptane. The fluorocarbon compounds in comparative examples 5.2–5.4 failed across the board in the repellency tests except comparative 5.2 was able to repel the Drakeol #34 compound. In comparative example 5.5, the fluorocarbon dispersion passed the repellency test for Isopropanol (90/10) and Drakeol #34, but it had complete wetting in the repellency of n-heptane and n-decane.